Retort for underfeed stokers



July 12, 193s.

2 Sheets-Sheet 2 J. C. BOHMKER4 RETORT FOR UNDERFEED sToKERs FiledApril' 22, 1957 4 5 tion.

Patented July i938.

PATE'NT oFFlcE RETORT FOR UNDERFEED STOKERS Joh'n C. Bohmker, kee, Ill.Application April 22, 1937, Serial No. 138,403

14 Clama.

This invention relates to retorts orburners for automatic coalstokersand particularly to improvements in the construction of -suchdevices and the means for distributing air for combus- The main objectsof this invention are to provide an improved retort construction; toprovide an improved arrangement for distribution of air .to the interiorof the retort and to the surround- Ving fuel bed; to provide aretortconstruction in which the tuyres are less likely to become chokedor clogged; to provide an improved tuyre construction; to provide animproved tuyre arrange ment whereby 4air will be distributed equally to15 all parts of the fuel bed; and to provide an improved and simplifiedretort construction wherein burned'out or damaged sections can bereadily replaced. I

vAn illustrative embodiment of this invention is shown in theaccompanying drawings in which: Fig. l is a perspective view of theimproved coal-burning retort and it's fuel supply tube.

Fig. 2 is' an enlarged plan view of the same showing its formation andarrangement. V Fig. 3 is an enlarged fragmentary detail taken on lineA3--3 of Fig. 2 illustrating the tuyre ar-` rangement.

Fig. i is an enlarged fragmentary sectional view taken on line 4-4 ofFig. 3 `showing the arrangement, oi tuyres for lateral air distributionto l the surrounding fuel bed. A

Fig. 5 is a sectional view of the improved retort as taken on line 5 5of Fig. 2, showing the same as positioned in thecombustionchamber of afurnace. or boiler.

Fig. 6 is a sectional -view taken online G--B of Fig. 5 showing thearrangement oi the lower tuyre ring.

Fig. 7 is a similar view taken online 'i-i of 40 Fig. 5 showing thearrangement of the upper tuyre ring and,`

Fig. 'd isv a fragmentary perspectivgdetail of the vtuyine ringsillustrating the interlockingmeans for the tuyre ringsand thearrangement oi air channels leading to the' uppermost air ports.

In the form shown in the drawings, my improved retort comprises abase`section i, a 'top section or shell vtand a retort body within saidshell comprising an upwardly extending body Vmember or ring t, a lowertuyre memberl or ring t, and an vupper tuyre member or ring t; allarranged to provide an open ended retort into which coal ior combustionIis supplied by a worinC conveyor t. operating in a conveyor tube i and(Ci. 11o-45) entering the retort through an intake 8 leading into anupwardly curved throat portion i which discharges upwardly into the bodyring i of the retort. y The throat portion d is formed integral with gthe retort base i and the door iii of the throat is curvedv upwardly in-a mathematical curve which is known as the Schiele antifriction curve.This construction of the retort thro'at equalizes the friction over thecurved oor of the same so jm that less power is required to force thei'uel from the conveyor tinto the retort.

As shown, the tuyere rings t and 5 are arranged to iit and nest oneabove the other, ontop of the body ring 3. `The retort shell t is spacedaway 1l from the retort body and is formed with an inwardly turnedflange-like portion il at its upper end and the inner margin oftheportion ii is turned downwardly so as to nestingly engage the uppertuyre ring 5. Thus, means is provided to 2o connect the vertical sidewall of the shell t with the upper edge of the uppermost tuyrev ring tand close off the space between the shell ii and the retort body.

, The body ring 3 and the tuyre rings t and t 2li are formed so thatwhen -assembledthe retort will have a smooth upwardly and outwardlysloping side wall which extends ush with the inner margin of theinturned portion il of the shell 2. thus forming a retort pot whichextends upward- 30 ly :from the throat portion d with a graduallyincreasing horizontal area.

The body ring 3, which is shownin the form of an invertedtruncated cone,is arranged to ht onto Athe throat portion t as shown in Fig'. 5 and 35a lug or key i2 is provided on the bottom margin ofthe body ring 3 forinterlocking engagement with a notch formed inthe upper edge of thethroat 9, so that when the body ring 3 is set thereon; its properangular position will be hxed. The M purpose of so positioning the ring3 will subsequently be shown.

The upper margin oi the ring' t is proy vided with an annular groove i3Yon its 'inner M periphery to receive a depending annular hangelikeportion it on the inner lower margin oi the tuyre ring t which isarranged to be nestingly set upon the body ring i.

Also the inner upper margin oi the tuyre ring 5u i is provided with asimilar groove it into which an annular depending ange it on the innerbotyprovidea seat into which a downwardly extending lip I1 of theinwardly-turned portion I I of the shell 2 is-arranged to set.

Thus, when the several rings comprising the pot or body portion of theretort are properly assembled and the shell 2 is set thereupon andbolted down to the base'portion I, the entire retortbecomes a unit inwhich the several parts are securely locked together.

As shown, the tm're rings 4 and 5 are arranged to provide angularlyspaced horizontal slot-like ports or tuyres I9 and I9 respectively,which ports providecommunication between the interior of the retort andspace 20 between the shell 2 and the retort rings. 'I'he Ispace 20communicates with an air space 2I surrounding the throat portion 9 ofthe retort base and the space 2I leads to openings 22 and 23 disposed oneither side of the throat inlet portion 8. The opening 22 is arrangedfor connection to an air supply duct 24 and the opening 29 is arrangedas a vcleanoutpassage for the removal of ily ash. Thus, air deliveredinto the opening 22 circulates through the space 2I surrounding thethroat portion 9 and thence upwardly into the space 20,

surrounding the retort b^ody or pot, from which i it passes through theports I9 and I9 into the interior of the retort.,

In order to provide for the lateral distribution of air to the fuel bedabove and surrounding the top of the retort, a plurality of spaced ports25 are provided in the upper ilange-like portion II of the shell 2. Asshown, the ports 25 communicate with the air space 20 within the shell 2vertically, through the inwardly-turned portion II, and each air port 25is provided with a roundedhood 26 which ist integral on the flange-likeportion Il and which is shaped to direct air from the ports 25` radiallyoutward from the upper end of the retort and into the surrounding bed offuel. The several hoods project upwardly above the inturned portion IIof the shell 2 and are in the nature of an angularly spaced series ofbosses. Also, as shown, each of the hoods is tapered inwardly toward theaxis of the retort.

As shown in Figures 6 and '1, the air ports or tuyres I8 and I9 arespaced angularly relative to`the axis of the tuyre rings and are formedby providing horizontal peripherally extending slots in the uppersurface of the tuyre rings, vas by cutting away or omitting portionsfrom the tuyre ring surface and, as shown, each port or slot extendsinto the ledge or shoulder formed by the inner peripheral groove at theupper margin of the tuyre ring; thus each port is stepped downwardly asshown in Figure 5, so as to clear the annular flange at the bottom ofthe member next above. Y.

In order to provide for equal distribution of air for combustion, theair ports or tuyres I9 of the tuyre ring 5, which is nearest to theburning fuel bed, are of varying size in the peripheral direction',vthough their centers are equally spaced apart angularly, andthedisposition of the airports I9 is particularly arranged so that thelargest ports are at the location of the lowest pressure in 'the airspace 20 surrounding the tuyre rings.

Since the incoming air for combustion enters ythe base portion of theyretort at'bne side thereof, in the direction shownv by the arrow 21 inFigs. v2 and 7, parallel to the" fore and aft'. center line, indicatedby the' lin'e -A- A in Fig. 7, it will be apparent that the air pressurein the .space 20 will varyV according tothe distance from the point ofentry. Hence, if the retort is considered as being divided intoquadrants by the transverse center line B-B the first quadrant I willhave the highest pressure and the thirdquadrant III will have the lowestpressure. IV have,a substantially equal pressure, for the reason that,in the arrangement shown, the incoming air divides in the quadrant I andpasses in both clockwise and counterclockwise directions toward quadrantIII.

Thus, the air ports I9 in quadrant I are made to be the smallest and theair ports in quadrant III are made to be the largest. 'I'he air ports inquadrants II and IV are substantially equal and4 are of a sizeintermediate the sizes for quadrants I and III. In this manner thevolume of air passing through the several air ports I9 will besubstantially equal for each air port around the entire periphery of thetuyre ring.

While 'such an arrangement of the air ports I 8 in the tuyre ring 4 isnot shown herein, it will be understood that the air ports I 8 may bealso of graduated sizes according to the quadrant in which they arelocated. L

In order that the tuyre rings 4 and 5 will be certain of proper angularlocation relative to the several quadrants, the tuyre ring 4 is keyed tothe body ring 3 as at 28, Fig. 8, and the tuyre ring is keyed to thetuyre ring 4 as at 29,' the body ring 3 being keyed to the mouth of thethroat portion 9 by the lug I2 as shown in Fig. 5.

As shown in Figs. 3, 5, and 8, the tuyre ring 5 is notched or groovedvertically on its outer peripheral surface, opposite each of the airports 25 at the top of the shell 2, as indicated at 30. to provide achannel or guide to direct air from the space 20 to the air ports 25,Also in order to provide equal distribution of air to and through theair ports 25, the upper tuyre ring 5 is formed so that its upper outerperipheral edge is eccentric relative to the axis of the ring 5, asshown in Fig. 7. Thus the outermost periphery of the tuyre ring 5 isnearest the wall of the shell 2 in quadrant I and farthest from the wallof the shell 2 in the quadrant III, in this manner serving to block oilor throttle the air passing to the air ports 25 in the quadrant I, Whilethe air ports 25 in the quadrant4 III are permitted a larger spacethrough which air can pass from the air space 20.

. It will now be seen that the herein described arrangement, acoal-burning retort of simplified construction and lower cost ofmanufacture is provided; and likewise by means of the construction, anequal distribution of air to all parts of the fuel bed is accomplishedautomatically, regardless of the amount of air that is delivered to thewind box or air space 2|, in the base portion I, through the air supplyduct 24 which is preferably connected to a motor-driven blower, notshown.

Quadrants II and I In use the improved retort is set into the ash pit ofa furnace or boiler, so as to be centrallyl positioned therein. Theretort is set up by first placing the base portion I and then settingthereupon the retort body ring 3 and the tuyre rings 4 and 5 after whichthe shell 2 is set in position and bolted down, as indicated in Fig. -l.The furnace or boiler ash pit isvthen filled in with a'suitablerefractory material up to a level about one inch or an inch and a halfbelow the hooded openings of the air ports 25; from which point therefractory material is tapered upwardly toward the side walls-of thelfurnace or'looilei combustion chamber.

amasar means of a screw or worin conveyor il and upwardly therethroughinto the furnace combustion chamber, Where .it `tends to dow outwardly`*toward the side walls of the same.

As the coal is supplied upwardly through-the retort from the throatportion d, air for combustion is at the same time supplied to the windbox 2i and combustion takes place at the top portion of the retort,spreading outwardly through the bed of fuel above the retorttoward thesides of the furnace combustion chamber.

Because of the equal distribution of air, accomplished by the-hereindescribed tuyre arrangement, the fuel is ,burned uniformly about theentire periphery of the retort and the portionoi: the iuel bed lyingimmediately within the top portionof the retort is uniformly heated.

The hooded lateral ports l at the top of the retort serve to distributeair tothe surrounding bed of fuel and at the same time boss-like hoodsld serveto break up the solid mass or body oi thecoal as it reaches thetop edgevoi the retort and is forced over the same into the space beyondor surrounding the retort. Thus, free access of air into the mass oifuel is assured to promote uniform and complete combustion.

fuel upward through the retort in no way obstructs the hooded air portstil and while the air f ports or tuyres it and it are'feimosed toclogging by reason of sliding contact with the iuel, the fact that theyare extended in a horizontal direction, instead of a vertical directionas is usually the case, tends to minimize such obstruction.

The main advantages oi my improved retort lie in the'simplicity of itsconstruction and its readily replaceable parts as well as in the ar'-rangement providing for a more equitable dis@ tribution of combustionair to the fuel bed.

Other advantages lie in the substantially nonclogging arrangement of theair ports or tuyres opening into the interior of the retort: and in thehooded tuyre openings or air ports it v which deliver air laterallyoutwardly from the upper portion oi the retort, the hoods serving notonly to prevent clogging oi these lateral air ports but also servingtobreak upthe mass of fuel as it flows over the top edge of the retort.

it will be understood, that, while the retort herein shown anddescribed, is oi a circular construction, the invention herein set forthis equally applicable to other retort shapes such as an an upwardlyextending open-ended body, a shell spaced from and surrounding saidbody, flangelike means connecting `the upper ends of said shell and bodyand closing oi the space therebetween, and a hollow support for saidshell opening upwardlyinto said space and having a 1`ateral air inlet,said body having a plurality ofV perimetrically spaced portstherethrough communicating with the said space, said ports beingproportioned to provide a progressively increasing port area insuccessive predetermined perimetrlc segments oi said body as saidsegments become perimetrically remote from the location oi said airinlet and a decreased port area as said 'segments again approach saidair inlet location in the same 'perimetric direction.

2. A retort of the class described comprising an upwardly extendingopen-ended body, a shell spaced laterally froman'd surrounding saidbody,

lill

ange-lilre'means connectingl the upper ends of said shell and body andclosing oil` the vspace therebetween, and a hollow support for saidshell opening upwardly into 'said space and having a lateral air inlet,said body having a 'plurality of vertically narrow horizontallyextending perimetrically spaced ports in its side wall communicatingwith the said space, said ports increasing in horizontal length as theyprogress in both perimetric directions from the side of said bodyadjacent said air inlet to the opposite side thereoi'.

A 3. 'A retort comprising an upwardly extending body member, a pair ofhorizontally disposed tuyre members fitted one upon the other .and uponthe upper end of said body member, each oi said tuyre members having aplurality oi ports .perlmetrically spaced in its side wall', said portsvbeing proportioned to provide a greater port area in one side of saidretort than in the opposite side thereof, a shell member spacedlaterally from and surrounding said body and tuyere members, said shellmember having an inwardly turned upper margin nttingly engaging themargin of the uppermost tuyre member, and

'a hollow base supporting said shell member, said base having upwardcommunication with vthe space between said shell and bodymembers and alateral air inlet located adjacent the side ci said retort having thesmallest port openings.

d. il retort comprising an upwardly extending body member, a pairoil-horizontally disposed tuyere members fitted one upon the other andupon the upper end of said body member, each of sel said tuyere vmembershaving a plurality or" ports perirnetrically spaced in its side wall;vsaid ports being proportioned to provide a progressively increasingportarea in successive predetermined perimetric segments oi' said retortwhich segments progress in both perimetric directions from one side oisaid retort to the opposite side thereof, a shell member spaced from andsurrounding said body and tuyere members, said shell member having aninwardly turned upper margin flttingly engaging the margin oi theuppermost tuyre membei', and a hollow' base supporting said shellmember, said base having upward communication with the space betweensaid shell and body members and a; lateral air inlet `located adjacentthe side oi said retort having the smallest port openings.

5. A retort of the class described comprising an upwardly extendingopen-ended body, a shell spaced from and surrounding said body,dangelihe means connecting the upper margins of said shell and saidbody, and a plurality of hollow perimetricallyspaced bosses projectingupwardly from the upper surface of said flange-like means, said hollow.bosses each having communication with the space between said shell andbody and Y laterally outbill upwardly extending open-ended body, a shellspaced from and surrounding said body, iiangelike means connecting theupper margins of said shell and said body, and a plurality of hollowinwardly tapered perimetrically spaced bosses projecting upwardly fromsaid flange-like means, said bosses each having a port opening laterallyoutward relative to said shell, and said dangelike means having spacedports providing communication between said hollow bosses and the spacebetween said shell and body. 4

7. A retort of the class described comprising an upwardly extendingopen-ended body, a shell spaced laterally from and surrounding, saidbody, means connecting the top of said shell and the upper margin oirsaid body. said last-named means having a plurality of perimetricallyspaced ports communicating with the space between said shell and saidbody, a hood covering each of said ports and opening laterally outwardrelative to said shell, said body and shell being arranged to provide aprogressively increasing width of the space between their respectiveside walls and in the vicinity of said ports in both perimetricdirections from one side of said retort to the opposite side thereof. K

. 8. A retort comprising an annular open-ended upwardly extending bodymember, a pair of an- `nular tuyre rings fitted one upon the other andupon the upper end of said body member, each of said tuyre rings havinga plurality of angularly spaced tuyres opening through its side wall,said tuyres being arranged to provide a progressively increasing tuyreopening area in successive predetermined angular segments of said retortin both angular directions from one side of said retort to the oppositeside thereof, an annular shell member spaced from and surrounding saidbody member and tuyre rings, means connecting the margins of said shelland the uppermost tuyre ring to close oit' the space therebetween, and aplurality of angularly spaced hollow bosses projecting upwardly fromsaid last-named means, said bosses having communication with the spacebetween said shell and tuyre rings and a port opening radially outwardrelative to said retort.

9. A retort comprising an annular open-ended upwardly extending bodymember, a pair of annular tuyre rings iitted one upon the other and uponthe upper end of said body member, each of said tuyre rings having aplurality of angularly spaced tuyres opening through its side wall, saidtuyres being arranged to provide a progressively increasing tuyreopening area in successive predetermined angular segments of said retortin both angular directions from one side of said retort to the oppositeside thereof, an annular shell member spaced from and surrounding saidbody member and tuyre rings, means connecting the margins of said shelland the uppermost tuyre ring to close off the space therebetween, saidlastnamed means having a plurality oi angularly spacedV openingstherethrough communicating with the said closed olf space each coveredby a vertically projecting hood-like boss, said bosses each having aport opening radially outward from said retort, and the uppermost tuyrering having its outer margin eccentric relative to the inner wall ofsaid shell to throttle certain of said lastnamed openings.

10. In a device of the class described, a tuyre member comprising anannular ring having a plurality of angularly spaced horizontallyextending slot--like tuyre openings in its side wall and an outei`periphery eccentric relative to its inner periphery, said tuyre openingsbeing of varying length as they progress angularly about, said ring fromthe place of greatest eccentricity of said peripheries.

11. In a device of the class described, a ringlike tuyre member having aplurality of tuyre openings spaced along its side wall, said tilyremember being formed with the center of the area defined by its outerperimeter offset laterally relative to the center of the area defined bythe inner periphery.

12. In a device of the class described, a tuyre member comprising anannular ring having a plurality of angularly spaced tuyre openings inits sidewall, said tuyre member being formed with its outer peripheryeccentric relative to its inner periphery.

13. A retort of the class described, comprising an inwardly extendingopen-ended body, a shell spaced laterally from and surrounding saidbody, means connecting the top oi' said shell and the upper margin ofsaid body, said last-named means having a plurality of laterally openingperimetrically spaced ports communicating with the space between saidshell and saidy body, and said body and shell being arranged to providea progressively increasing width of the space between their respectivesidewalls and in the vicinity of said ports in both perimetricdirections from one side of said retort to the opposite side thereof.

14. A-retort of the class described, comprising an inwardly extendingopen-endedbody, a shell spaced laterally from and concentricallysurrounding said body, means connecting the top of said shell and theupper margin of said body, said last-named means having a plurality o1'perimet- ,rically spaced ports communicating with the JOHN C. BOHMIKER.

